Mechanism to give holographic objects saliency in multiple spaces

ABSTRACT

A system for allowing a virtual object to interact with other virtual objects across different spaces within an augmented reality (AR) environment and to transition between the different spaces is described. An AR environment may include a plurality of spaces, each comprising a bounded area or volume within the AR environment. In one example, an AR environment may be associated with a three-dimensional world space and a two-dimensional object space corresponding with a page of a book within the AR environment. A virtual object within the AR environment may be assigned to the object space and transition from the two-dimensional object space to the three-dimensional world space upon the detection of a space transition event. In some cases, a dual representation of the virtual object may be used to detect interactions between the virtual object and other virtual objects in both the world space and the object space.

BACKGROUND

Augmented reality (AR) relates to providing an augmented real-worldenvironment where the perception of a real-world environment (or datarepresenting a real-world environment) is augmented or modified withcomputer-generated virtual data. For example, data representing areal-world environment may be captured in real-time using sensory inputdevices such as a camera or microphone and augmented withcomputer-generated virtual data including virtual images and virtualsounds. The virtual data may also include information related to thereal-world environment such as a text description associated with areal-world object in the real-world environment. The objects within anAR environment may include real objects (i.e., objects that exist withina particular real-world environment) and virtual objects (i.e., objectsthat do not exist within the particular real-world environment).

In order to realistically integrate virtual objects into an ARenvironment, an AR system typically performs several tasks includingmapping and localization. Mapping relates to the process of generating amap of a real-world environment. Localization relates to the process oflocating a particular point of view or pose relative to the map of thereal-world environment. In some cases, an AR system may localize thepose of a mobile device moving within a real-world environment inreal-time in order to determine the particular view associated with themobile device that needs to be augmented as the mobile device moveswithin the real-world environment.

SUMMARY

Technology is described for allowing a virtual object to interact withother virtual objects across different spaces within an augmentedreality (AR) environment and to transition between the different spaces.An AR environment may include a plurality of spaces, each comprising abounded area or volume within the AR environment. In one example, an ARenvironment may be associated with a three-dimensional world space and atwo-dimensional object space corresponding with a page of a book withinthe AR environment. A virtual object within the AR environment may beassigned to the object space and transition from the two-dimensionalobject space to the three-dimensional world space upon the detection ofa space transition event. In some cases, a dual representation of thevirtual object may be used to detect interactions between the virtualobject and other virtual objects in both the world space and the objectspace.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of one embodiment of a networked computingenvironment in which the disclosed technology may be practiced.

FIG. 2A depicts one embodiment of a mobile device in communication witha second mobile device.

FIG. 2B depicts one embodiment of a portion of an HMD.

FIG. 2C depicts one embodiment of a portion of an HMD in which gazevectors extending to a point of gaze are used for aligning a farinter-pupillary distance (IPD).

FIG. 2D depicts one embodiment of a portion of an HMD in which gazevectors extending to a point of gaze are used for aligning a nearinter-pupillary distance (IPD).

FIG. 2E depicts one embodiment of a portion of an HMD with movabledisplay optical systems including gaze detection elements.

FIG. 2F depicts an alternative embodiment of a portion of an HMD withmovable display optical systems including gaze detection elements.

FIG. 2G depicts one embodiment of a side view of a portion of an HMD.

FIG. 2H depicts one embodiment of a side view of a portion of an HMDwhich provides support for a three dimensional adjustment of amicrodisplay assembly.

FIG. 3 depicts one embodiment of a computing system including a capturedevice and computing environment.

FIGS. 4A-4D provide examples of various environments in which one ormore virtual objects associated with an augmentable book may begenerated and displayed to an end user of an HMD.

FIGS. 5A-5D provide examples of various environments in which a virtualobject may transition from a three-dimensional space to atwo-dimensional space and then back to the three-dimensional space.

FIG. 6A is a flowchart describing one embodiment of a method forgenerating and displaying one or more virtual objects in one or moredifferent spaces associated with an augmented reality environment.

FIG. 6B is a flowchart describing one embodiment of a process forassigning and mapping a virtual object to a particular space.

FIG. 6C is a flowchart describing one embodiment of a process fordetecting an interaction with a virtual object.

FIG. 6D is a flowchart describing one embodiment of a process fordetermining whether a space transition event has occurred.

FIG. 7 is a flowchart describing an alternative embodiment of a methodfor generating and displaying one or more virtual objects in one or moredifferent spaces associated with an augmented reality environment.

FIG. 8 is a block diagram of one embodiment of a mobile device.

DETAILED DESCRIPTION

Technology is described for allowing a virtual object to interact withother virtual objects across different spaces within an augmentedreality (AR) environment and to transition between the different spaces.An AR environment may include a plurality of spaces. Each space of theplurality of spaces may comprise a bounded area or volume within the ARenvironment and be associated with one or more physics constraints. Theone or more physics constraints may determine the simulated effects ofvarious physics properties such as gravity (e.g., a weak or stronginfluence), time (e.g., a fast or slow environment), and lighting oneach of the virtual objects within a particular space of the pluralityof spaces. In one example, an AR environment may be associated with athree-dimensional world space corresponding with a real-worldenvironment and a two-dimensional object space corresponding with a realobject (e.g., a page of a book) within the AR environment. A virtualobject within the AR environment may be assigned or locked to the objectspace and transition from the two-dimensional object space to thethree-dimensional world space upon the detection of a space transitionevent. By locking the virtual object to the object space, the virtualobject may appear attached to the real object or confined to a boundaryof the object space. The space transition event may comprise thedetection of the virtual object reaching a boundary of the object spaceor the detection of a space triggering event. In some cases, a dualrepresentation of the virtual object may be used to detect interactionsbetween the virtual object and other virtual objects in both the worldspace and the object space. The dual representation allows a virtualobject to interact with other virtual objects in both the world spaceand the object space even though the virtual object may only be assignedto either the world space or the object space at a particular time.

In some embodiments, a plurality of spaces associated with an ARenvironment may include a top-level world space and one or more objectspaces corresponding with one or more real objects within the ARenvironment. The one or more object spaces may move with respect to thetop-level world space. The one or more object spaces may correspond with2D or 3D spaces associated with various real objects within anenvironment such as a book, a page in a book, a table, a table top, aparticular person's hand, a particular person's shirt, and a wall. Theone or more object spaces may correspond with one or more user-centricspaces.

In some embodiments, a virtual object may comprise a first portion ofthe virtual object and a second portion of the virtual object. The firstportion of the virtual object may be assigned to a first space within anAR environment and the second portion of the virtual object may beassigned to a second space within the AR environment different from thefirst space. In one example, the first portion of the virtual object maycomprise a virtual house and the second portion of the virtual objectmay comprise virtual smoke being emitted from the virtual house. Thevirtual house may be assigned to an object space corresponding with apage of an augmentable book and the virtual smoke (or a portion of thevirtual smoke) may be assigned to a world space for the AR environmentupon the detection that the virtual smoke (or a portion of the virtualsmoke) has reached a boundary of the page. Thus, the virtual object maystraddle two different spaces within the AR environment. In this case,the virtual house may comprise a two-dimensional virtual object withinthe boundaries of the object space and the virtual smoke may comprise athree-dimensional virtual object within the world space.

In some embodiments, a virtual object within an AR environment may havea different sensitivity to triggering events based on the particularspace to which the virtual object is currently assigned. In one example,two virtual objects comprising a red virtual ball and a blue virtualball may be assigned to a 2D space corresponding with a table top. Thered virtual ball and the blue virtual ball may interact with each otherand virtually bounce off of each other as long as they are both assignedto the 2D space. However, once the red virtual ball and the blue virtualball leave the 2D space and enter the world space, then they may notinteract with each other in the same manner. In another example, one ormore triggering events based on the detection of a person's gaze may beapplied to virtual objects within the 2D space, but not to other virtualobjects within the world space. In some cases, gazing at or focusing ona virtual object within the 2D space for more than a particular periodof time may cause a space transitioning event. However, once the virtualobject is within the world space, gazing at the virtual object may notcause a space transitioning event.

One issue regarding the education of children and youth involvesfacilitating and encouraging the reading of stories, as well asimproving reading comprehension. Moreover, complex stories includingmultiple characters and subplots (e.g., a Shakespeare play) may beconfusing to inexperienced readers or otherwise difficult to followthereby preventing the readers from fully enjoying the readingexperience. Thus, there is a need for an augmented reality systemcapable of generating and displaying holographic visual aids related toa story in order to enhance the reading experience of the story and toreward the reading of the story.

In one embodiment, a virtual object may comprise a holographic visualaid associated with an AR tag on a particular page of an augmentablebook. The holographic visual aid may be assigned to a 2D spacecorresponding with the particular page. In one example, the holographicvisual aid may comprise a virtual house emitting virtual smoke into the2D space. Within the 2D space, the virtual smoke may appear as atwo-dimensional virtual object rising towards a boundary of the 2Dspace. Once the virtual smoke (or a portion thereof) reaches theboundary of the 2D space, then the virtual smoke may transition to the3D world space and appear as a three-dimensional virtual object withinthe 3D world space. In some cases, the movement of the virtual smokewithin the 2D space may correspond with a slow motion animation (i.e.,time appears to move slowly within the 2D space as compared with the 3Dworld space). Moreover, the movement of the virtual smoke within the 2Dspace may not be influenced by a virtual wind within the 2D space,whereas once the virtual smoke transitions to the 3D world space, then avirtual wind may be applied to the virtual smoke. The virtual wind maybe determined based on a predefined wind speed and direction or acquiredbased on weather information associated with a location of ahead-mounted display device (HMD) displaying the virtual object.

FIG. 1 is a block diagram of one embodiment of a networked computingenvironment 100 in which the disclosed technology may be practiced.Networked computing environment 100 includes a plurality of computingdevices interconnected through one or more networks 180. The one or morenetworks 180 allow a particular computing device to connect to andcommunicate with another computing device. The depicted computingdevices include mobile device 11, mobile device 12, mobile device 19,and server 15. In some embodiments, the plurality of computing devicesmay include other computing devices not shown. In some embodiments, theplurality of computing devices may include more than or less than thenumber of computing devices shown in FIG. 1. The one or more networks180 may include a secure network such as an enterprise private network,an unsecure network such as a wireless open network, a local areanetwork (LAN), a wide area network (WAN), and the Internet. Each networkof the one or more networks 180 may include hubs, bridges, routers,switches, and wired transmission media such as a wired network ordirect-wired connection.

Server 15, which may comprise a supplemental information server or anapplication server, may allow a client to download information (e.g.,text, audio, image, and video files) from the server or to perform asearch query related to particular information stored on the server. Ingeneral, a “server” may include a hardware device that acts as the hostin a client-server relationship or a software process that shares aresource with or performs work for one or more clients. Communicationbetween computing devices in a client-server relationship may beinitiated by a client sending a request to the server asking for accessto a particular resource or for particular work to be performed. Theserver may subsequently perform the actions requested and send aresponse back to the client.

One embodiment of server 15 includes a network interface 155, processor156, memory 157, and translator 158, all in communication with eachother. Network interface 155 allows server 15 to connect to one or morenetworks 180. Network interface 155 may include a wireless networkinterface, a modem, and/or a wired network interface. Processor 156allows server 15 to execute computer readable instructions stored inmemory 157 in order to perform processes discussed herein. Translator158 may include mapping logic for translating a first file of a firstfile format into a corresponding second file of a second file format(i.e., the second file may be a translated version of the first file).Translator 158 may be configured using file mapping instructions thatprovide instructions for mapping files of a first file format (orportions thereof) into corresponding files of a second file format.

One embodiment of mobile device 19 includes a network interface 145,processor 146, memory 147, camera 148, sensors 149, and display 150, allin communication with each other. Network interface 145 allows mobiledevice 19 to connect to one or more networks 180. Network interface 145may include a wireless network interface, a modem, and/or a wirednetwork interface. Processor 146 allows mobile device 19 to executecomputer readable instructions stored in memory 147 in order to performprocesses discussed herein. Camera 148 may capture color images and/ordepth images. Sensors 149 may generate motion and/or orientationinformation associated with mobile device 19. In some cases, sensors 149may comprise an inertial measurement unit (IMU). Display 150 may displaydigital images and/or videos. Display 150 may comprise a see-throughdisplay.

In some embodiments, various components of mobile device 19 includingthe network interface 145, processor 146, memory 147, camera 148, andsensors 149 may be integrated on a single chip substrate. In oneexample, the network interface 145, processor 146, memory 147, camera148, and sensors 149 may be integrated as a system on a chip (SOC). Inother embodiments, the network interface 145, processor 146, memory 147,camera 148, and sensors 149 may be integrated within a single package.

In some embodiments, mobile device 19 may provide a natural userinterface (NUI) by employing camera 148, sensors 149, and gesturerecognition software running on processor 146. With a natural userinterface, a person's body parts and movements may be detected,interpreted, and used to control various aspects of a computingapplication. In one example, a computing device utilizing a natural userinterface may infer the intent of a person interacting with thecomputing device (e.g., that the end user has performed a particulargesture in order to control the computing device).

Networked computing environment 100 may provide a cloud computingenvironment for one or more computing devices. Cloud computing refers toInternet-based computing, wherein shared resources, software, and/orinformation are provided to one or more computing devices on-demand viathe Internet (or other global network). The term “cloud” is used as ametaphor for the Internet, based on the cloud drawings used in computernetworking diagrams to depict the Internet as an abstraction of theunderlying infrastructure it represents.

In one example, mobile device 19 comprises a head-mounted display device(HMD) that provides an augmented reality environment or a mixed realityenvironment to an end user of the HMD. The HMD may comprise a videosee-through and/or an optical see-through system. An optical see-throughHMD worn by an end user may allow actual direct viewing of a real-worldenvironment (e.g., via transparent lenses) and may, at the same time,project images of a virtual object into the visual field of the end userthereby augmenting the real-world environment perceived by the end userwith the virtual object.

Utilizing an HMD, an end user may move around a real-world environment(e.g., a living room) wearing the HMD and perceive views of thereal-world overlaid with images of virtual objects. The virtual objectsmay appear to maintain coherent spatial relationship with the real-worldenvironment (i.e., as the end user turns their head or moves within thereal-world environment, the images displayed to the end user will changesuch that the virtual objects appear to exist within the real-worldenvironment as perceived by the end user). The virtual objects may alsoappear fixed with respect to the end user's point of view (e.g., avirtual menu that always appears in the top right corner of the enduser's point of view regardless of how the end user turns their head ormoves within the real-world environment). In one embodiment,environmental mapping of the real-world environment may be performed byserver 15 (i.e., on the server side) while camera localization may beperformed on mobile device 19 (i.e., on the client side). The virtualobjects may include a text description associated with a real-worldobject.

In some embodiments, a mobile device, such as mobile device 19, may bein communication with a server in the cloud, such as server 15, and mayprovide to the server location information (e.g., the location of themobile device via GPS coordinates) and/or image information (e.g.,information regarding objects detected within a field of view of themobile device) associated with the mobile device. In response, theserver may transmit to the mobile device one or more virtual objectsbased upon the location information and/or image information provided tothe server. In one embodiment, the mobile device 19 may specify aparticular file format for receiving the one or more virtual objects andserver 15 may transmit to the mobile device 19 the one or more virtualobjects embodied within a file of the particular file format.

In some embodiments, a mobile device, such as mobile device 19, may beused to provide an AR environment in which one or more virtual objectsmay be viewed as existing within or being bound to a first space withinthe AR environment. The one or more virtual objects may transition fromthe first space within the AR environment to a second space within theAR environment different from the first space. The first space maycomprise a 2D space and the second space may comprise a 3D space. Theone or more virtual objects may comprise holographic visual aidsassociated with a reading object (e.g., a virtual character or animationassociated with the reading object). The reading object may comprise abook, magazine, or piece of literature. In one example, a first HMDassociated with a child reading an augmentable book may identify an ARtag on a particular page of the reading object and display a holographicvisual aid corresponding with the AR tag within a 2D space associatedwith the particular page. The identity of the AR tag may be representedby a poster index or a numerical tag identifier associated with the ARtag. The first HMD may then detect a space transition event causing theholographic visual aid to transition from the 2D space associated withthe particular page to the three-dimensional world space. The spacetransition event may comprise the detection of the holographic visualaid reaching a boundary of the 2D space.

FIG. 2A depicts one embodiment of a mobile device 19 in communicationwith a second mobile device 5. Mobile device 19 may comprise asee-through HMD. As depicted, mobile device 19 communicates with mobiledevice 5 via a wired connection 6. However, the mobile device 19 mayalso communicate with mobile device 5 via a wireless connection. Mobiledevice 5 may be used by mobile device 19 in order to offload computeintensive processing tasks (e.g., the rendering of virtual objects) andto store virtual object information and other data that may be used toprovide an augmented reality environment on mobile device 19.

FIG. 2B depicts one embodiment of a portion of an HMD, such as mobiledevice 19 in FIG. 1. Only the right side of an HMD 200 is depicted. HMD200 includes right temple 202, nose bridge 204, eye glass 216, and eyeglass frame 214. Right temple 202 includes a capture device 213 (e.g., afront facing camera and/or microphone) in communication with processingunit 236. The capture device 213 may include one or more cameras forrecording digital images and/or videos and may transmit the visualrecordings to processing unit 236. The one or more cameras may capturecolor information, IR information, and/or depth information. The capturedevice 213 may also include one or more microphones for recording soundsand may transmit the audio recordings to processing unit 236.

Right temple 202 also includes biometric sensor 220, eye tracking system221, ear phones 230, motion and orientation sensor 238, GPS receiver232, power supply 239, and wireless interface 237, all in communicationwith processing unit 236. Biometric sensor 220 may include one or moreelectrodes for determining a pulse or heart rate associated with an enduser of HMD 200 and a temperature sensor for determining a bodytemperature associated with the end user of HMD 200. In one embodiment,biometric sensor 220 includes a pulse rate measuring sensor whichpresses against the temple of the end user. Motion and orientationsensor 238 may include a three axis magnetometer, a three axis gyro,and/or a three axis accelerometer. In one embodiment, the motion andorientation sensor 238 may comprise an inertial measurement unit (IMU).The GPS receiver may determine a GPS location associated with HMD 200.Processing unit 236 may include one or more processors and a memory forstoring computer readable instructions to be executed on the one or moreprocessors. The memory may also store other types of data to be executedon the one or more processors.

In one embodiment, the eye tracking system 221 may include an inwardfacing camera. In another embodiment, the eye tracking system 221 maycomprise an eye tracking illumination source and an associated eyetracking IR sensor. In one embodiment, the eye tracking illuminationsource may include one or more infrared (IR) emitters such as aninfrared light emitting diode (LED) or a laser (e.g. VCSEL) emittingabout a predetermined IR wavelength or a range of wavelengths. In someembodiments, the eye tracking sensor may include an IR camera or an IRposition sensitive detector (PSD) for tracking glint positions. Moreinformation about eye tracking systems can be found in U.S. Pat. No.7,401,920, entitled “Head Mounted Eye Tracking and Display System”,issued Jul. 22, 2008, and U.S. patent application Ser. No. 13/245,700,entitled “Integrated Eye Tracking and Display System,” filed Sep. 26,2011, both of which are herein incorporated by reference.

In one embodiment, eye glass 216 may comprise a see-through display,whereby images generated by processing unit 236 may be projected and/ordisplayed on the see-through display. The capture device 213 may becalibrated such that a field of view captured by the capture device 213corresponds with the field of view as seen by an end user of HMD 200.The ear phones 230 may be used to output sounds associated with theprojected images of virtual objects. In some embodiments, HMD 200 mayinclude two or more front facing cameras (e.g., one on each temple) inorder to obtain depth from stereo information associated with the fieldof view captured by the front facing cameras. The two or more frontfacing cameras may also comprise 3D, IR, and/or RGB cameras. Depthinformation may also be acquired from a single camera utilizing depthfrom motion techniques. For example, two images may be acquired from thesingle camera associated with two different points in space at differentpoints in time. Parallax calculations may then be performed givenposition information regarding the two different points in space.

In some embodiments, HMD 200 may perform gaze detection for each eye ofan end user's eyes using gaze detection elements and a three-dimensionalcoordinate system in relation to one or more human eye elements such asa cornea center, a center of eyeball rotation, or a pupil center. Gazedetection may be used to identify where the end user is focusing withina field of view. Examples of gaze detection elements may include glintgenerating illuminators and sensors for capturing data representing thegenerated glints. In some cases, the center of the cornea can bedetermined based on two glints using planar geometry. The center of thecornea links the pupil center and the center of rotation of the eyeball,which may be treated as a fixed location for determining an optical axisof the end user's eye at a certain gaze or viewing angle.

FIG. 2C depicts one embodiment of a portion of an HMD 2 in which gazevectors extending to a point of gaze are used for aligning a farinter-pupillary distance (IPD). HMD 2 is one example of a mobile device,such as mobile device 19 in FIG. 1. As depicted, gaze vectors 180 l and180 r intersect at a point of gaze that is far away from the end user(i.e., the gaze vectors 180 l and 180 r do not intersect as the end useris looking at an object far away). A model of the eyeball for eyeballs160 l and 160 r is illustrated for each eye based on the Gullstrandschematic eye model. Each eyeball is modeled as a sphere with a centerof rotation 166 and includes a cornea 168 modeled as a sphere having acenter 164. The cornea 168 rotates with the eyeball, and the center ofrotation 166 of the eyeball may be treated as a fixed point. The cornea168 covers an iris 170 with a pupil 162 at its center. On the surface172 of each cornea are glints 174 and 176.

As depicted in FIG. 2C, a sensor detection area 139 (i.e., 139 l and 139r, respectively) is aligned with the optical axis of each displayoptical system 14 within an eyeglass frame 115. In one example, thesensor associated with the detection area may include one or morecameras capable of capturing image data representing glints 174 l and176 l generated respectively by illuminators 153 a and 153 b on the leftside of the frame 115 and data representing glints 174 r and 176 rgenerated respectively by illuminators 153 c and 153 d on the right sideof the frame 115. Through the display optical systems 14 l and 14 r inthe eyeglass frame 115, the end user's field of view includes both realobjects 190, 192, and 194 and virtual objects 182 and 184.

The axis 178 formed from the center of rotation 166 through the corneacenter 164 to the pupil 162 comprises the optical axis of the eye. Agaze vector 180 may also be referred to as the line of sight or visualaxis which extends from the fovea through the center of the pupil 162.In some embodiments, the optical axis is determined and a smallcorrection is determined through user calibration to obtain the visualaxis which is selected as the gaze vector. For each end user, a virtualobject may be displayed by the display device at each of a number ofpredetermined positions at different horizontal and vertical positions.An optical axis may be computed for each eye during display of theobject at each position, and a ray modeled as extending from theposition into the user's eye. A gaze offset angle with horizontal andvertical components may be determined based on how the optical axis mustbe moved to align with the modeled ray. From the different positions, anaverage gaze offset angle with horizontal or vertical components can beselected as the small correction to be applied to each computed opticalaxis. In some embodiments, only a horizontal component is used for thegaze offset angle correction.

As depicted in FIG. 2C, the gaze vectors 180 l and 180 r are notperfectly parallel as the vectors become closer together as they extendfrom the eyeball into the field of view at a point of gaze. At eachdisplay optical system 14, the gaze vector 180 appears to intersect theoptical axis upon which the sensor detection area 139 is centered. Inthis configuration, the optical axes are aligned with theinter-pupillary distance (IPD). When an end user is looking straightahead, the IPD measured is also referred to as the far IPD.

FIG. 2D depicts one embodiment of a portion of an HMD 2 in which gazevectors extending to a point of gaze are used for aligning a nearinter-pupillary distance (IPD). HMD 2 is one example of a mobile device,such as mobile device 19 in FIG. 1. As depicted, the cornea 168 l of theleft eye is rotated to the right or towards the end user's nose, and thecornea 168 r of the right eye is rotated to the left or towards the enduser's nose. Both pupils are gazing at a real object 194 within aparticular distance of the end user. Gaze vectors 180 l and 180 r fromeach eye enter the Panum's fusional region 195 in which real object 194is located. The Panum's fusional region is the area of single vision ina binocular viewing system like that of human vision. The intersectionof the gaze vectors 180 l and 180 r indicates that the end user islooking at real object 194. At such a distance, as the eyeballs rotateinward, the distance between their pupils decreases to a near IPD. Thenear IPD is typically about 4 mm less than the far IPD. A near IPDdistance criteria (e.g., a point of gaze at less than four feet from theend user) may be used to switch or adjust the IPD alignment of thedisplay optical systems 14 to that of the near IPD. For the near IPD,each display optical system 14 may be moved toward the end user's noseso the optical axis, and detection area 139, moves toward the nose a fewmillimeters as represented by detection areas 139 ln and 139 rn.

More information about determining the IPD for an end user of an HMD andadjusting the display optical systems accordingly can be found in U.S.patent application Ser. No. 13/250,878, entitled “Personal Audio/VisualSystem,” filed Sep. 30, 2011, which is herein incorporated by referencein its entirety.

FIG. 2E depicts one embodiment of a portion of an HMD 2 with movabledisplay optical systems including gaze detection elements. What appearsas a lens for each eye represents a display optical system 14 for eacheye (i.e., 14 l and 14 r). A display optical system includes asee-through lens and optical elements (e.g. mirrors, filters) forseamlessly fusing virtual content with the actual direct real world viewseen through the lenses of the HMD. A display optical system 14 has anoptical axis which is generally in the center of the see-through lens inwhich light is generally collimated to provide a distortionless view.For example, when an eye care professional fits an ordinary pair ofeyeglasses to an end user's face, the glasses are usually fit such thatthey sit on the end user's nose at a position where each pupil isaligned with the center or optical axis of the respective lens resultingin generally collimated light reaching the end user's eye for a clear ordistortionless view.

As depicted in FIG. 2E, a detection area 139 r, 139 l of at least onesensor is aligned with the optical axis of its respective displayoptical system 14 r, 14 l so that the center of the detection area 139r, 139 l is capturing light along the optical axis. If the displayoptical system 14 is aligned with the end user's pupil, then eachdetection area 139 of the respective sensor 134 is aligned with the enduser's pupil. Reflected light of the detection area 139 is transferredvia one or more optical elements to the actual image sensor 134 of thecamera, which in the embodiment depicted is illustrated by the dashedline as being inside the frame 115.

In one embodiment, the at least one sensor 134 may be a visible lightcamera (e.g., an RGB camera). In one example, an optical element orlight directing element comprises a visible light reflecting mirrorwhich is partially transmissive and partially reflective. The visiblelight camera provides image data of the pupil of the end user's eye,while IR photodetectors 152 capture glints which are reflections in theIR portion of the spectrum. If a visible light camera is used,reflections of virtual images may appear in the eye data captured by thecamera. An image filtering technique may be used to remove the virtualimage reflections if desired. An IR camera is not sensitive to thevirtual image reflections on the eye.

In another embodiment, the at least one sensor 134 (i.e., 134 l and 134r) is an IR camera or a position sensitive detector (PSD) to which theIR radiation may be directed. The IR radiation reflected from the eyemay be from incident radiation of the illuminators 153, other IRilluminators (not shown), or from ambient IR radiation reflected off theeye. In some cases, sensor 134 may be a combination of an RGB and an IRcamera, and the light directing elements may include a visible lightreflecting or diverting element and an IR radiation reflecting ordiverting element. In some cases, the sensor 134 may be embedded withina lens of the system 14. Additionally, an image filtering technique maybe applied to blend the camera into a user field of view to lessen anydistraction to the user.

As depicted in FIG. 2E, there are four sets of an illuminator 153 pairedwith a photodetector 152 and separated by a barrier 154 to avoidinterference between the incident light generated by the illuminator 153and the reflected light received at the photodetector 152. To avoidunnecessary clutter in the drawings, drawing numerals are shown withrespect to a representative pair. Each illuminator may be an infra-red(IR) illuminator which generates a narrow beam of light at about apredetermined wavelength. Each of the photodetectors may be selected tocapture light at about the predetermined wavelength. Infra-red may alsoinclude near-infrared. As there can be wavelength drift of anilluminator or photodetector or a small range about a wavelength may beacceptable, the illuminator and photodetector may have a tolerance rangeabout a wavelength for generation and detection. In some embodimentswhere the sensor is an IR camera or IR position sensitive detector(PSD), the photodetectors may include additional data capture devicesand may also be used to monitor the operation of the illuminators, e.g.wavelength drift, beam width changes, etc. The photodetectors may alsoprovide glint data with a visible light camera as the sensor 134.

As depicted in FIG. 2E, each display optical system 14 and itsarrangement of gaze detection elements facing each eye (e.g., such ascamera 134 and its detection area 139, the illuminators 153, andphotodetectors 152) are located on a movable inner frame portion 117 l,117 r. In this example, a display adjustment mechanism comprises one ormore motors 203 having a shaft 205 which attaches to the inner frameportion 117 which slides from left to right or vice versa within theframe 115 under the guidance and power of shafts 205 driven by motors203. In some embodiments, one motor 203 may drive both inner frames.

FIG. 2F depicts an alternative embodiment of a portion of an HMD 2 withmovable display optical systems including gaze detection elements. Asdepicted, each display optical system 14 is enclosed in a separate frameportion 115 l, 115 r. Each of the frame portions may be moved separatelyby the motors 203. More information about HMDs with movable displayoptical systems can be found in U.S. patent application Ser. No.13/250,878, entitled “Personal Audio/Visual System,” filed Sep. 30,2011, which is herein incorporated by reference in its entirety.

FIG. 2G depicts one embodiment of a side view of a portion of an HMD 2including an eyeglass temple 102 of the frame 115. At the front of frame115 is a front facing video camera 113 that can capture video and stillimages. In some embodiments, front facing camera 113 may include a depthcamera as well as a visible light or RGB camera. In one example, thedepth camera may include an IR illuminator transmitter and a hotreflecting surface like a hot mirror in front of the visible imagesensor which lets the visible light pass and directs reflected IRradiation within a wavelength range or about a predetermined wavelengthtransmitted by the illuminator to a CCD or other type of depth sensor.Other types of visible light cameras (e.g., an RGB camera or imagesensor) and depth cameras can be used. More information about depthcameras can be found in U.S. patent application Ser. No. 12/813,675,filed on Jun. 11, 2010, incorporated herein by reference in itsentirety. The data from the cameras may be sent to control circuitry 136for processing in order to identify objects through image segmentationand/or edge detection techniques.

Inside temple 102, or mounted to temple 102, are ear phones 130,inertial sensors 132, GPS transceiver 144, and temperature sensor 138.In one embodiment, inertial sensors 132 include a three axismagnetometer, three axis gyro, and three axis accelerometer. Theinertial sensors are for sensing position, orientation, and suddenaccelerations of HMD 2. From these movements, head position may also bedetermined.

In some cases, HMD 2 may include an image generation unit which cancreate one or more images including one or more virtual objects. In someembodiments, a microdisplay may be used as the image generation unit. Asdepicted, microdisplay assembly 173 comprises light processing elementsand a variable focus adjuster 135. An example of a light processingelement is a microdisplay unit 120. Other examples include one or moreoptical elements such as one or more lenses of a lens system 122 and oneor more reflecting elements such as surfaces 124. Lens system 122 maycomprise a single lens or a plurality of lenses.

Mounted to or inside temple 102, the microdisplay unit 120 includes animage source and generates an image of a virtual object. Themicrodisplay unit 120 is optically aligned with the lens system 122 andthe reflecting surface 124. The optical alignment may be along anoptical axis 133 or an optical path 133 including one or more opticalaxes. The microdisplay unit 120 projects the image of the virtual objectthrough lens system 122, which may direct the image light ontoreflecting element 124. The variable focus adjuster 135 changes thedisplacement between one or more light processing elements in theoptical path of the microdisplay assembly or an optical power of anelement in the microdisplay assembly. The optical power of a lens isdefined as the reciprocal of its focal length (i.e., 1/focal length) soa change in one effects the other. The change in focal length results ina change in the region of the field of view which is in focus for animage generated by the microdisplay assembly 173.

In one example of the microdisplay assembly 173 making displacementchanges, the displacement changes are guided within an armature 137supporting at least one light processing element such as the lens system122 and the microdisplay 120. The armature 137 helps stabilize thealignment along the optical path 133 during physical movement of theelements to achieve a selected displacement or optical power. In someexamples, the adjuster 135 may move one or more optical elements such asa lens in lens system 122 within the armature 137. In other examples,the armature may have grooves or space in the area around a lightprocessing element so it slides over the element, for example,microdisplay 120, without moving the light processing element. Anotherelement in the armature such as the lens system 122 is attached so thatthe system 122 or a lens within slides or moves with the moving armature137. The displacement range is typically on the order of a fewmillimeters (mm). In one example, the range is 1-2 mm. In otherexamples, the armature 137 may provide support to the lens system 122for focal adjustment techniques involving adjustment of other physicalparameters than displacement. An example of such a parameter ispolarization.

More information about adjusting a focal distance of a microdisplayassembly can be found in U.S. patent Ser. No. 12/941,825 entitled“Automatic Variable Virtual Focus for Augmented Reality Displays,” filedNov. 8, 2010, which is herein incorporated by reference in its entirety.

In one embodiment, the adjuster 135 may be an actuator such as apiezoelectric motor. Other technologies for the actuator may also beused and some examples of such technologies are a voice coil formed of acoil and a permanent magnet, a magnetostriction element, and anelectrostriction element.

Several different image generation technologies may be used to implementmicrodisplay 120. In one example, microdisplay 120 can be implementedusing a transmissive projection technology where the light source ismodulated by optically active material and backlit with white light.These technologies are usually implemented using LCD type displays withpowerful backlights and high optical energy densities. Microdisplay 120can also be implemented using a reflective technology for which externallight is reflected and modulated by an optically active material. Theillumination may be forward lit by either a white source or RGB source,depending on the technology. Digital light processing (DLP), liquidcrystal on silicon (LCOS) and Mirasol® display technology from Qualcomm,Inc. are all examples of reflective technologies which are efficient asmost energy is reflected away from the modulated structure and may beused in the system described herein. Additionally, microdisplay 120 canbe implemented using an emissive technology where light is generated bythe display. For example, a PicoP™ engine from Microvision, Inc. emits alaser signal with a micro mirror steering either onto a tiny screen thatacts as a transmissive element or beamed directly into the eye (e.g.,laser).

FIG. 2H depicts one embodiment of a side view of a portion of an HMD 2which provides support for a three dimensional adjustment of amicrodisplay assembly. Some of the numerals illustrated in the FIG. 2Gabove have been removed to avoid clutter in the drawing. In someembodiments where the display optical system 14 is moved in any of threedimensions, the optical elements represented by reflecting surface 124and the other elements of the microdisplay assembly 173 may also bemoved for maintaining the optical path 133 of the light of a virtualimage to the display optical system. An XYZ transport mechanism in thisexample made up of one or more motors represented by motor block 203 andshafts 205 under control of control circuitry 136 control movement ofthe elements of the microdisplay assembly 173. An example of motorswhich may be used are piezoelectric motors. In the illustrated example,one motor is attached to the armature 137 and moves the variable focusadjuster 135 as well, and another representative motor 203 controls themovement of the reflecting element 124.

FIG. 3 depicts one embodiment of a computing system 10 including acapture device 20 and computing environment 12. In some embodiments,capture device 20 and computing environment 12 may be integrated withina single mobile computing device. The single integrated mobile computingdevice may comprise a mobile device, such as mobile device 19 in FIG. 1.In one example, the capture device 20 and computing environment 12 maybe integrated within an HMD. In other embodiments, capture device 20 maybe integrated with a first mobile device, such as mobile device 19 inFIG. 2A, and computing environment 12 may be integrated with a secondmobile device in communication with the first mobile device, such asmobile device 5 in FIG. 2A.

In one embodiment, the capture device 20 may include one or more imagesensors for capturing images and videos. An image sensor may comprise aCCD image sensor or a CMOS image sensor. In some embodiments, capturedevice 20 may include an IR CMOS image sensor. The capture device 20 mayalso include a depth sensor (or depth sensing camera) configured tocapture video with depth information including a depth image that mayinclude depth values via any suitable technique including, for example,time-of-flight, structured light, stereo image, or the like.

The capture device 20 may include an image camera component 32. In oneembodiment, the image camera component 32 may include a depth camerathat may capture a depth image of a scene. The depth image may include atwo-dimensional (2D) pixel area of the captured scene where each pixelin the 2D pixel area may represent a depth value such as a distance in,for example, centimeters, millimeters, or the like of an object in thecaptured scene from the image camera component 32.

The image camera component 32 may include an IR light component 34, athree-dimensional (3D) camera 36, and an RGB camera 38 that may be usedto capture the depth image of a capture area. For example, intime-of-flight analysis, the IR light component 34 of the capture device20 may emit an infrared light onto the capture area and may then usesensors to detect the backscattered light from the surface of one ormore objects in the capture area using, for example, the 3D camera 36and/or the RGB camera 38. In some embodiments, pulsed infrared light maybe used such that the time between an outgoing light pulse and acorresponding incoming light pulse may be measured and used to determinea physical distance from the capture device 20 to a particular locationon the one or more objects in the capture area. Additionally, the phaseof the outgoing light wave may be compared to the phase of the incominglight wave to determine a phase shift. The phase shift may then be usedto determine a physical distance from the capture device to a particularlocation associated with the one or more objects.

In another example, the capture device 20 may use structured light tocapture depth information. In such an analysis, patterned light (i.e.,light displayed as a known pattern such as grid pattern or a stripepattern) may be projected onto the capture area via, for example, the IRlight component 34. Upon striking the surface of one or more objects (ortargets) in the capture area, the pattern may become deformed inresponse. Such a deformation of the pattern may be captured by, forexample, the 3-D camera 36 and/or the RGB camera 38 and analyzed todetermine a physical distance from the capture device to a particularlocation on the one or more objects. Capture device 20 may includeoptics for producing collimated light. In some embodiments, a laserprojector may be used to create a structured light pattern. The lightprojector may include a laser, laser diode, and/or LED.

In some embodiments, two or more different cameras may be incorporatedinto an integrated capture device. For example, a depth camera and avideo camera (e.g., an RGB video camera) may be incorporated into acommon capture device. In some embodiments, two or more separate capturedevices of the same or differing types may be cooperatively used. Forexample, a depth camera and a separate video camera may be used, twovideo cameras may be used, two depth cameras may be used, two RGBcameras may be used, or any combination and number of cameras may beused. In one embodiment, the capture device 20 may include two or morephysically separated cameras that may view a capture area from differentangles to obtain visual stereo data that may be resolved to generatedepth information. Depth may also be determined by capturing imagesusing a plurality of detectors that may be monochromatic, infrared, RGB,or any other type of detector and performing a parallax calculation.Other types of depth image sensors can also be used to create a depthimage.

As depicted in FIG. 3, capture device 20 may include one or moremicrophones 40. Each of the one or more microphones 40 may include atransducer or sensor that may receive and convert sound into anelectrical signal. The one or more microphones may comprise a microphonearray in which the one or more microphones may be arranged in apredetermined layout.

The capture device 20 may include a processor 42 that may be inoperative communication with the image camera component 32. Theprocessor 42 may include a standardized processor, a specializedprocessor, a microprocessor, or the like. The processor 42 may executeinstructions that may include instructions for storing filters orprofiles, receiving and analyzing images, determining whether aparticular situation has occurred, or any other suitable instructions.It is to be understood that at least some image analysis and/or targetanalysis and tracking operations may be executed by processors containedwithin one or more capture devices such as capture device 20.

The capture device 20 may include a memory 44 that may store theinstructions that may be executed by the processor 42, images or framesof images captured by the 3D camera or RGB camera, filters or profiles,or any other suitable information, images, or the like. In one example,the memory 44 may include random access memory (RAM), read only memory(ROM), cache, Flash memory, a hard disk, or any other suitable storagecomponent. As depicted, the memory 44 may be a separate component incommunication with the image capture component 32 and the processor 42.In another embodiment, the memory 44 may be integrated into theprocessor 42 and/or the image capture component 32. In otherembodiments, some or all of the components 32, 34, 36, 38, 40, 42 and 44of the capture device 20 may be housed in a single housing.

The capture device 20 may be in communication with the computingenvironment 12 via a communication link 46. The communication link 46may be a wired connection including, for example, a USB connection, aFireWire connection, an Ethernet cable connection, or the like and/or awireless connection such as a wireless 802.11b, g, a, or n connection.The computing environment 12 may provide a clock to the capture device20 that may be used to determine when to capture, for example, a scenevia the communication link 46. In one embodiment, the capture device 20may provide the images captured by, for example, the 3D camera 36 and/orthe RGB camera 38 to the computing environment 12 via the communicationlink 46.

As depicted in FIG. 3, computing environment 12 includes image and audioprocessing engine 194 in communication with application 196. Application196 may comprise an operating system application or other computingapplication such as a gaming application. Image and audio processingengine 194 includes virtual data engine 197, object and gesturerecognition engine 190, structure data 198, processing unit 191, andmemory unit 192, all in communication with each other. Image and audioprocessing engine 194 processes video, image, and audio data receivedfrom capture device 20. To assist in the detection and/or tracking ofobjects, image and audio processing engine 194 may utilize structuredata 198 and object and gesture recognition engine 190. Virtual dataengine 197 processes virtual objects and registers the position andorientation of virtual objects in relation to various maps of areal-world environment stored in memory unit 192.

Processing unit 191 may include one or more processors for executingobject, facial, and voice recognition algorithms. In one embodiment,image and audio processing engine 194 may apply object recognition andfacial recognition techniques to image or video data. For example,object recognition may be used to detect particular objects (e.g.,soccer balls, cars, people, or landmarks) and facial recognition may beused to detect the face of a particular person. Image and audioprocessing engine 194 may apply audio and voice recognition techniquesto audio data. For example, audio recognition may be used to detect aparticular sound. The particular faces, voices, sounds, and objects tobe detected may be stored in one or more memories contained in memoryunit 192. Processing unit 191 may execute computer readable instructionsstored in memory unit 192 in order to perform processes discussedherein.

The image and audio processing engine 194 may utilize structural data198 while performing object recognition. Structure data 198 may includestructural information about targets and/or objects to be tracked. Forexample, a skeletal model of a human may be stored to help recognizebody parts. In another example, structure data 198 may includestructural information regarding one or more inanimate objects in orderto help recognize the one or more inanimate objects.

The image and audio processing engine 194 may also utilize object andgesture recognition engine 190 while performing gesture recognition. Inone example, object and gesture recognition engine 190 may include acollection of gesture filters, each comprising information concerning agesture that may be performed by a skeletal model. The object andgesture recognition engine 190 may compare the data captured by capturedevice 20 in the form of the skeletal model and movements associatedwith it to the gesture filters in a gesture library to identify when auser (as represented by the skeletal model) has performed one or moregestures. In one example, image and audio processing engine 194 may usethe object and gesture recognition engine 190 to help interpretmovements of a skeletal model and to detect the performance of aparticular gesture.

In some embodiments, one or more objects being tracked may be augmentedwith one or more markers such as an IR retroreflective marker to improveobject detection and/or tracking. Planar reference images, coded ARmarkers, QR codes, and/or bar codes may also be used to improve objectdetection and/or tracking. Upon detection of one or more objects and/orgestures, image and audio processing engine 194 may report toapplication 196 an identification of each object or gesture detected anda corresponding position and/or orientation if applicable.

More information about detecting and tracking objects can be found inU.S. patent application Ser. No. 12/641,788, “Motion Detection UsingDepth Images,” filed on Dec. 18, 2009; and U.S. patent application Ser.No. 12/475,308, “Device for Identifying and Tracking Multiple Humansover Time,” both of which are incorporated herein by reference in theirentirety. More information about object and gesture recognition engine190 can be found in U.S. patent application Ser. No. 12/422,661,“Gesture Recognizer System Architecture,” filed on Apr. 13, 2009,incorporated herein by reference in its entirety. More information aboutrecognizing gestures can be found in U.S. patent application Ser. No.12/391,150, “Standard Gestures,” filed on Feb. 23, 2009; and U.S. patentapplication Ser. No. 12/474,655, “Gesture Tool,” filed on May 29, 2009,both of which are incorporated by reference herein in their entirety.

FIGS. 4A-4D provide examples of various environments in which one ormore virtual objects (e.g., a holographic visual aid) associated with anaugmentable book may be generated and displayed to an end user of an HMDwhile the end user is reading the augmentable book. In some cases, theone or more virtual objects may transition from a two-dimensional spacecorresponding with a page of the augmentable book into thethree-dimensional world space based on a detection of a space transitionevent.

FIG. 4A depicts one embodiment of a reading object 21 as seen by an enduser wearing an HMD, such as mobile device 19 in FIG. 1. The readingobject may comprise a book, magazine, or piece of literature. Readingobject 21 includes an augmented reality (AR) tag 25. The AR tag 25 maycomprise an image or graphic that may be used to determine one or morevirtual objects to display associated with the AR tag 25 such as aholographic visual aid. The AR tag 25 may also be used to determine alocation on the reading object 21 in which to place the one or morevirtual objects. In some embodiments, a reading object may comprise anexisting book without any predetermined AR tags (e.g., a book publishedin 1969). In this case, the existing book may be retrofitted with an ARtag by identifying distinctive words or pictures associated with aparticular page of the existing book without any predetermined AR tags.

FIG. 4B depicts one embodiment of an augmented reality environment asseen by an end user wearing an HMD, such as mobile device 19 in FIG. 1.As depicted, the reading object 21 of FIG. 4A has been augmented with avirtual object 26 in a location determined by the AR tag 25 of FIG. 4A.The virtual object 26 may comprise a static image or a dynamicholographic animation comprising a sequence of images. As the virtualobject 26 is displayed or overlaid over the reading object 21 asperceived through the see-through lenses of the HMD, the end user of theHMD may perceive that the virtual object 26 is part of (or attached to)the reading object 21. In some cases, the virtual object 26 may bevisually attached to the reading object 21 (e.g., the referencecoordinates for virtual object 26 may be relative to a coordinate spaceassociated with the reading object 21). In this case, as the readingobject 21 is moved within a field of view of an HMD, the virtual object26 will appear fixed to the reading object.

FIG. 4C depicts one embodiment of an augmented reality environment 410as seen by an end user wearing an HMD, such as mobile device 19 inFIG. 1. As depicted, the augmented reality environment 410 includes areading object 21 and a virtual object 26 bound to a 2D space associatedwith a page of the reading object 21. As the virtual object 26 isdisplayed or overlaid over the real-world environment as perceivedthrough the see-through lenses of the HMD, the end user of the HMD mayperceive that the virtual object 26 is bound to or confined to the 2Dspace associated with the page.

FIG. 4D depicts one embodiment of an augmented reality environment 410as seen by an end user wearing an HMD, such as mobile device 19 inFIG. 1. As depicted, the augmented reality environment 410 has beenaugmented with a virtual object 27 corresponding with the virtual object26 in FIG. 4C. The virtual object 27 may be bound to a 3D spaceassociated with the augmented reality environment 410 in which thereading object 21 exists. As the virtual object 27 is displayed oroverlaid over the real-world environment as perceived through thesee-through lenses of the HMD, the end user of the HMD may perceive thatthe virtual object 27 exists within or is confined to the 3D spaceassociated with the augmented reality environment 410. In oneembodiment, the HMD may detect a space transition event causing thevirtual object 26 in FIG. 4C to transition from the 2D space associatedwith the page of reading object 21 to a three-dimensional world space.The space transition event may comprise the detection of the virtualobject 26 in FIG. 4C reaching a boundary of the 2D space (e.g., the endsof the page or a picture boundary). The space transition event may alsocomprise the detection of a particular gesture performed by the end userof the HMD (e.g., a hand gesture pointing at the virtual object 26 inFIG. 4C).

FIGS. 5A-5D provide examples of various environments in which a virtualobject may transition from a three-dimensional space to atwo-dimensional space and then back to the three-dimensional space. Insome cases, the virtual object may comprise a virtual sphere or ball.When the virtual object is assigned to the three-dimensional space, thevirtual object may comprise a three-dimensional virtual object (e.g., avirtual object comprising a virtual ball may appear as a sphere). Whenthe virtual object is assigned to the two-dimensional space, the virtualobject may comprise a two-dimensional virtual object (e.g., a virtualobject comprising a virtual ball may appear as a circle). Thethree-dimensional space may comprise a three-dimensional world space andthe two-dimensional space may comprise a two-dimensional spacecorresponding with the top of a table within an environment.

FIG. 5A depicts one embodiment of an augmented reality environment 510as seen by an end user wearing an HMD, such as mobile device 19 inFIG. 1. As depicted, the augmented reality environment 510 includes atwo-dimensional object 52 and a virtual object 53 assigned to thethree-dimensional world space of the augmented reality environment 510.The virtual object 53 may appear as a three-dimensional sphere fallingtowards the ground. As depicted in FIG. 5B, once the virtual object 53enters a two-dimensional space corresponding with the two-dimensionalobject 52, the virtual object 53 may transition from thethree-dimensional world space to the two-dimensional space correspondingwith the two-dimensional object 52. In this case, the virtual object 53may be mapped to a two-dimensional representation of the virtual object53 comprising a two-dimensional virtual object 54 (e.g., athree-dimensional sphere may be mapped to a two-dimensional circle). Asdepicted in FIG. 5C, once the two-dimensional virtual object 54 isassigned or confined to the two-dimensional space corresponding with thetwo-dimensional object 52, it may appear to move according to one ormore physics constraints associated with the two-dimensional space(e.g., the simulated effects of gravity may cause the two-dimensionalvirtual object 54 to fall from one side of the two-dimensional space toanother side of the two-dimensional space). As depicted in FIG. 5D, oncethe two-dimensional virtual object 54 has reached a boundary of thetwo-dimensional space corresponding with the two-dimensional object 52,then the two-dimensional virtual object 54 may transition from thetwo-dimensional space back to the three-dimensional world space.

FIG. 6A is a flowchart describing one embodiment of a method forgenerating and displaying one or more virtual objects in one or moredifferent spaces associated with an augmented reality environment. Inone embodiment, the process of FIG. 6A is performed by a mobile device,such as mobile device 19 in FIG. 1.

In step 602, an environment associated with a mobile device isidentified. The environment may be identified via GPS coordinates or viaimage recognition of particular features or landmarks within theenvironment. In one example, the environment may comprise a home or abedroom or living room within the home. The environment may include aplurality of spaces. Each space of the plurality of spaces may comprisea bounded area or volume within the environment and be associated withone or more physics constraints. The one or more physics constraints maydetermine the simulated effects of various physics properties such asgravity (e.g., a weak or strong influence), time (e.g., a fast or slowenvironment), and lighting on each of the virtual objects within aparticular space of the plurality of spaces. In one example, theenvironment may be associated with a three-dimensional world spacecorresponding with a real-world environment and a two-dimensional objectspace corresponding with a page of a reading object within theenvironment.

In step 604, a 3D map associated with the environment is acquired. The3D map may correspond with a common real-world coordinate systemassociated with the environment or a three-dimensional world spaceassociated with the environment. The 3D map may include models ofvarious landmarks or other environmental features associated with theenvironment. The 3D map may correspond with a top-level world space ofthe plurality of spaces. In step 606, one or more real objects withinthe environment are identified. The one or more real objects may beidentified via object and/or image recognition techniques. A first realobject of the one or more real objects may be associated with a firstspace of the plurality of spaces different from the world space of theplurality of spaces.

In step 608, one or more virtual objects associated with the environmentare acquired. The one or more virtual objects may be acquired from avirtual object server, such as server 15 in FIG. 1. The one or morevirtual objects may include a first virtual object. In one embodiment,the first virtual object may comprise a holographic visual aidassociated with the first real object.

In step 610, the first virtual object is assigned and mapped to aparticular space of the plurality of spaces. In one embodiment, thefirst virtual object may be assigned and mapped to the first spacecorresponding with the first real object. In another embodiment, thefirst virtual object may be assigned and mapped to the world spaceassociated with the environment. A virtual object may be assigned orlocked to a particular space (e.g., the first space). By locking thevirtual object to a particular space, the virtual object may appearattached to the particular space or confined within a boundary of theparticular space. In one embodiment, the particular space to which avirtual object is assigned may be the space in which the virtual objectappears salient. The mapping of a virtual object to a particular spacemay comprise determining a number of dimensions associated with theparticular space and mapping the virtual object to the number ofdimensions. For example, a three dimensional virtual object may bemapped to a two-dimensional space by finding a projection of thethree-dimensional virtual object onto the two-dimensional space. Oneembodiment of a process for assigning and mapping a virtual object to aparticular space is described later in reference to FIG. 6B.

In step 612, an interaction with the first virtual object is detected.The interaction may involve an interaction between the first virtualobject and one or more other virtual objects within the environment. Theone or more other virtual objects may comprise virtual objects withinthe same space (or assigned to the same space) as the first virtualobject or virtual objects that are in a different space (or assigned tothe different space) than that of the first virtual object. In oneembodiment, an interaction may occur when a location of the firstvirtual object coincides with one or more locations associated with theone or more other virtual objects. An interaction may cause the firstvirtual object to change a direction or speed of movement and/or itslocation within a particular space. One embodiment of a process fordetecting an interaction with a virtual object is described later inreference to FIG. 6C.

In step 614, it is determined whether a space transition event hasoccurred for the first virtual object. If it is determined that a spacetransition event has occurred for the first virtual object, then step616 is performed. Otherwise, if it is determined that a space transitionevent has not occurred for the first virtual object, then step 618 isperformed. In some cases, a space transition event may occur when avirtual object has reached a boundary of a particular space. A spacetransition event may also occur if a particular space triggering eventis detected. A space triggering event may comprise the detection of anend user of an HMD gazing at or focusing on the first virtual object forat least a particular period of time or the detection of a particulargesture performed by the end user of the HMD (e.g., the end user pointsat or touches images corresponding with the first virtual object). Oneembodiment of a process for determining whether a space transition eventhas occurred is described later in reference to FIG. 6D.

In step 616, the first virtual object is reassigned and remapped to anew space of the plurality of spaces. In one embodiment, the new spacemay comprise the world space corresponding with the environment. In step618, a location for the first virtual object within the environment isdetermined. In one embodiment, the location of the first virtual objectmay be relative to the world space corresponding with the environment.In another embodiment, the location of the first virtual object may berelative to the space to which the first virtual object is assigned(e.g., the particular space assigned in step 610 or the new spaceassigned in step 616). In some embodiments, the location of the firstvirtual object may be determined based on a six degree of freedom (6DOF)pose corresponding with the mobile device relative to the 3D map. A 6DOFpose may comprise information associated with the position andorientation of the mobile device within the environment. Moreinformation regarding determining a 6DOF pose can be found in U.S.patent application Ser. No. 13/152,220, “Distributed AsynchronousLocalization and Mapping for Augmented Reality,” incorporated herein byreference in its entirety.

In step 620, one or more images corresponding with the first virtualobject are rendered and displayed on the mobile device. The one or moreimages corresponding with the first virtual object may be rendered anddisplayed such that the first virtual object is perceived to existwithin the environment at a point in space corresponding with thelocation.

FIG. 6B is a flowchart describing one embodiment of a process forassigning and mapping a virtual object to a particular space. Theprocess described in FIG. 6B is one example of a process forimplementing step 610 in FIG. 6A. In one embodiment, the process of FIG.6B is performed by a mobile device, such as mobile device 19 in FIG. 1.

In step 632, an AR tag within an environment corresponding with avirtual object is detected. The identity of the AR tag may berepresented by a poster index or a numerical tag identifier associatedwith the AR tag. In step 634, an initial space for the virtual object isdetermined based on the AR tag. In one embodiment, the initial space isinferred from the object in which the AR tag is attached or affixed. Theinitial space may be determined by information embedded within the ARtag. In some cases, the initial space may comprise the world spacecorresponding with the environment or an object space corresponding witha real-world object.

In step 636, an initial location of the virtual object within theinitial space is determined. In one embodiment, the initial location maycorrespond with a center point of the AR tag. In another embodiment, theinitial location may be determined by information embedded within the ARtag. In one example, the initial location may be located at a particularoffset from the center point of the AR tag. In step 637, a dimension(e.g., a 2D or 3D space) of the initial space is determined. In somecases, the dimension of the initial space may be determined byinformation embedded within the AR tag. In some embodiments, the initialspace for the virtual object and the initial location for the virtualobject within the initial space may be specified as object properties ofthe virtual object.

In step 638, an initial object mapping for the virtual object isdetermined based on the dimension of the initial space. In oneembodiment, the virtual object may comprise a three-dimensional virtualobject and the dimension of the initial space may comprise atwo-dimensional space. In this case, the initial object mapping for thevirtual object may comprise a two-dimensional projection of thethree-dimensional virtual object onto the two-dimensional space. Inanother embodiment, the virtual object may comprise a two-dimensionalvirtual object and the dimension of the initial space may comprise athree-dimensional space. In this case, the initial object mapping forthe virtual object may comprise a two-dimensional representation of thetwo-dimensional object within the three-dimensional space. In step 639,the virtual object is assigned to the initial location within theinitial space and mapped to the initial object mapping.

FIG. 6C is a flowchart describing one embodiment of a process fordetecting an interaction with a virtual object. The process described inFIG. 6C is one example of a process for implementing step 612 in FIG.6A. In one embodiment, the process of FIG. 6C is performed by a mobiledevice, such as mobile device 19 in FIG. 1.

In step 652, a space and a location within the space associated with avirtual object are determined. In step 654, it is determined whether thevirtual object is assigned to the world space. If it is determined thatthe virtual object is assigned to the world space, then step 661 isperformed. Otherwise if it is determined that the virtual object is notassigned to the world space (i.e., the virtual object is assigned to anobject space), then step 656 is performed.

In step 656, it is detected that a real object associated with the spaceis within a particular distance of a different virtual object within theworld space. In this case, the real object associated with the spaceassociated with the virtual object may be in a proximity to a differentvirtual object within the world space. In order to check for potentialinteractions between the virtual object assigned to the space and thedifferent virtual object assigned to the world space, a dualrepresentation may be generated for the virtual object. In step 657, adual representation is generated for the virtual object. In oneembodiment, the dual representation comprises a first location for thevirtual object relative to the space and a second location for thevirtual object relative to the world space.

In step 658, it is detected that an interaction has occurred between thevirtual object and the different virtual object based on the dualrepresentation. In one embodiment, an interaction may be deemed to haveoccurred if a first location corresponding with the virtual object inthe world space overlaps with or is within a particular distance of asecond location corresponding with the different virtual object in theworld space.

In step 661, is detected that a real object associated with an objectspace is within a particular distance of the virtual object. In thiscase, the virtual object may be in proximity to a different virtualobject corresponding with the object space associated with the realobject. For example, a virtual object comprising a virtual ball may comewithin a particular distance of a real object comprising an augmentablebook. In order to check for potential interactions between the virtualobject assigned to the world space and the different virtual objectassigned to the object space, a dual representation may be generated forthe different virtual object.

In step 662, one or more other virtual objects associated with theobject space are determined. In step 663, one or more dualrepresentations are generated for the one or more other virtual objects.In some cases, a dual representation may be generated for each of theone or more other virtual objects. In one embodiment, the dualrepresentation may comprise a first location for a particular virtualobject relative to the object space and a second location for theparticular virtual object relative to the world space.

In step 664, it is detected that an interaction has occurred between thevirtual object and the one or more other virtual objects based on theone or more dual representations. In one embodiment, an interaction maybe deemed to have occurred if a first location corresponding with thevirtual object in the world space overlaps with or is within aparticular distance of one or more second locations corresponding withthe one or more other virtual objects in the world space.

FIG. 6D is a flowchart describing one embodiment of a process fordetermining whether a space transition event has occurred. The processdescribed in FIG. 6D is one example of a process for implementing step614 in FIG. 6A. In one embodiment, the process of FIG. 6D is performedby a mobile device, such as mobile device 19 in FIG. 1.

In step 672, a space and a location within the space associated with avirtual object are determined. In step 674, it is determined whether thevirtual object is able to transition from the space to a differentspace. In some embodiments, a virtual object may be locked to aparticular space and not allowed to transition from the particular spaceinto a different space. In step 676, it is detected that the virtualobject has reached a boundary of the space. In one embodiment, a virtualobject may be deemed to have reached a boundary of a particular spacewhen a location associated with the virtual object has reached a maximumrange of coordinates for the particular space (e.g., the virtual objecthas reached the boundary of a two-dimensional space associated with anaugmentable book).

In step 677, it is detected that a space triggering event associatedwith the virtual object has occurred. A space triggering event maycomprise the detection of an end user of an HMD gazing at or focusing onthe virtual object for at least a particular period of time or thedetection of a particular gesture performed by the end user of the HMD(e.g., the end user points at or touches images corresponding with thevirtual object).

In step 678, an identification of a space transition event may beoutputted in response to detecting that the virtual object has reachedthe boundary of the space. In some embodiments, the identification ofthe space transition event may be outputted in response to detectingthat the space triggering event has occurred. In one embodiment, theidentification of the space transition event may be outputted if it isdetected that both the virtual object has reached the boundary of thespace and that the space triggering event associated with the virtualobject has occurred.

FIG. 7 is a flowchart describing an alternative embodiment of a methodfor generating and displaying one or more virtual objects in one or moredifferent spaces associated with an augmented reality environment. Inone embodiment, the process of FIG. 7 is performed by a mobile device,such as mobile device 19 in FIG. 1.

In step 702, an environment associated with a mobile device isidentified. The environment may correspond with a world space. Theenvironment may be identified via GPS coordinates or via imagerecognition of particular features or landmarks within the environment.In one example, the environment may comprise a home or a bedroom orliving room within the home. The environment may include a plurality ofspaces. Each space of the plurality of spaces may comprise a boundedarea or volume within the environment and be associated with one or morephysics constraints. The one or more physics constraints may determinethe simulated effects of various physics properties such as gravity(e.g., a weak or strong influence), time (e.g., a fast or slowenvironment), and lighting on each of the virtual objects within aparticular space of the plurality of spaces. In one example, theenvironment may be associated with a three-dimensional world spacecorresponding with a real-world environment and a two-dimensional objectspace corresponding with a page of a reading object within theenvironment.

In step 704, a first AR tag associated with a first real object isdetected. The first real object may correspond with a first space (e.g.,a two-dimensional object space associated with the first real object).In step 706, a virtual object associated with the first AR tag isacquired. The virtual object may be acquired from a virtual objectserver, such as server 15 in FIG. 1. The virtual object may comprise afirst portion of the virtual object and a second portion of the virtualobject. In some embodiments, the first portion of the virtual object andthe second portion of the virtual object may be assigned to differentspaces within an augmented reality environment.

In step 708, the first portion of the virtual object is assigned andmapped to the first space corresponding with the first real object. Instep 709, the second portion of the virtual object is assigned andmapped to the first space corresponding with the first real object. Instep 710, a space transition event for the second portion of the virtualobject is detected. In one embodiment, the space transition event maycomprise the second portion of the virtual object reaching a boundary ofthe first space.

In step 712, the second portion of the virtual object is assigned andmapped to the world space in response to the space transition eventbeing detected. In step 714, one or more images corresponding with thevirtual object are rendered and displayed on the mobile device. The oneor more images corresponding with the virtual object may be rendered anddisplayed such that the first portion of the virtual object is perceivedto be locked to the first space and the second portion of a virtualobject is perceived to be locked to the world space.

In one embodiment, the first portion of the virtual object may comprisea virtual house and the second portion of the virtual object maycomprise virtual smoke being emitted from the virtual house. The virtualhouse may be assigned to the first space corresponding with a page of anaugmentable book. The virtual smoke (or a portion of the virtual smoke)may be assigned to the world space for the environment upon thedetection that the virtual smoke (or a portion of the virtual smoke) hasreached a boundary of the page. Thus, the virtual object may straddletwo different spaces within the environment. In this case, the virtualhouse may comprise a two-dimensional virtual object within theboundaries of the first space and the virtual smoke may comprise athree-dimensional virtual object within the world space.

One embodiment of the disclosed technology includes identifying one ormore real objects within an environment. The environment is associatedwith a world space. The one or more real objects include a first realobject associated with a first space different from the world space. Themethod further includes acquiring a virtual object associated with theenvironment, assigning the virtual object to the first space, detectinga space transition event for the virtual object, assigning the virtualobject to the world space in response to the detecting a spacetransition event, determining a location for the virtual object relativeto the world space, and displaying at the mobile device the virtualobject such that the virtual object is perceived to exist at a point inspace corresponding with the location.

One embodiment of the disclosed technology includes identifying anenvironment associated with a mobile device. The environment correspondswith a world space. The method further includes detecting a first AR tagassociated with a first real object within the environment. The firstreal object corresponds with a first space. The method further includesacquiring a virtual object associated with the first AR tag. The virtualobject comprises a first portion of the virtual object and a secondportion of the virtual object. The method further includes assigning thefirst portion of the virtual object to the first space, assigning thesecond portion of the virtual object to the first space, detecting aspace transition event for the second portion of the virtual object,assigning the second portion of the virtual object to the world space inresponse to the detecting a space transition event, and displaying atthe mobile device one or more images corresponding with the virtualobject such that the first portion of the virtual object is perceived tobe locked to the first space and the second portion of the virtualobject is perceived to be locked to the world space.

One embodiment of the disclosed technology includes a memory, one ormore processors, and a see-through display. The memory stores a virtualobject associated with an environment. The one or more processorsidentify one or more real objects within the environment. Theenvironment is associated with a world space. The one or more realobjects include a first real object associated with a first spacedifferent from the world space. The one or more processors assign thevirtual object to the first space, detect a space transition event forthe virtual object, assign the virtual object to the world space inresponse to detecting the space transition event, determine a locationfor the virtual object relative to the world space, and generate one ormore images of the virtual object corresponding with the location. Thesee-through display displays the one or more images of the virtualobject such that the virtual object is perceived to exist at a point inspace corresponding with the location.

FIG. 8 is a block diagram of one embodiment of a mobile device 8300,such as mobile device 19 in FIG. 1. Mobile devices may include laptopcomputers, pocket computers, mobile phones, personal digital assistants,and handheld media devices that have been integrated with wirelessreceiver/transmitter technology.

Mobile device 8300 includes one or more processors 8312 and memory 8310.Memory 8310 includes applications 8330 and non-volatile storage 8340.Memory 8310 can be any variety of memory storage media types, includingnon-volatile and volatile memory. A mobile device operating systemhandles the different operations of the mobile device 8300 and maycontain user interfaces for operations, such as placing and receivingphone calls, text messaging, checking voicemail, and the like. Theapplications 8330 can be any assortment of programs, such as a cameraapplication for photos and/or videos, an address book, a calendarapplication, a media player, an internet browser, games, an alarmapplication, and other applications. The non-volatile storage component8340 in memory 8310 may contain data such as music, photos, contactdata, scheduling data, and other files.

The one or more processors 8312 are in communication with a see-throughdisplay 8309. The see-through display 8309 may display one or morevirtual objects associated with a real-world environment. The one ormore processors 8312 also communicates with RF transmitter/receiver 8306which in turn is coupled to an antenna 8302, with infraredtransmitter/receiver 8308, with global positioning service (GPS)receiver 8365, and with movement/orientation sensor 8314 which mayinclude an accelerometer and/or magnetometer. RF transmitter/receiver8308 may enable wireless communication via various wireless technologystandards such as Bluetooth® or the IEEE 802.11 standards.Accelerometers have been incorporated into mobile devices to enableapplications such as intelligent user interface applications that letusers input commands through gestures, and orientation applicationswhich can automatically change the display from portrait to landscapewhen the mobile device is rotated. An accelerometer can be provided,e.g., by a micro-electromechanical system (MEMS) which is a tinymechanical device (of micrometer dimensions) built onto a semiconductorchip. Acceleration direction, as well as orientation, vibration, andshock can be sensed. The one or more processors 8312 further communicatewith a ringer/vibrator 8316, a user interface keypad/screen 8318, aspeaker 8320, a microphone 8322, a camera 8324, a light sensor 8326, anda temperature sensor 8328. The user interface keypad/screen may includea touch-sensitive screen display.

The one or more processors 8312 controls transmission and reception ofwireless signals. During a transmission mode, the one or more processors8312 provide voice signals from microphone 8322, or other data signals,to the RF transmitter/receiver 8306. The transmitter/receiver 8306transmits the signals through the antenna 8302. The ringer/vibrator 8316is used to signal an incoming call, text message, calendar reminder,alarm clock reminder, or other notification to the user. During areceiving mode, the RF transmitter/receiver 8306 receives a voice signalor data signal from a remote station through the antenna 8302. Areceived voice signal is provided to the speaker 8320 while otherreceived data signals are processed appropriately.

Additionally, a physical connector 8388 may be used to connect themobile device 8300 to an external power source, such as an AC adapter orpowered docking station, in order to recharge battery 8304. The physicalconnector 8388 may also be used as a data connection to an externalcomputing device. The data connection allows for operations such assynchronizing mobile device data with the computing data on anotherdevice.

The disclosed technology is operational with numerous other generalpurpose or special purpose computing system environments orconfigurations. Examples of well-known computing systems, environments,and/or configurations that may be suitable for use with the technologyinclude, but are not limited to, personal computers, server computers,hand-held or laptop devices, multiprocessor systems,microprocessor-based systems, set top boxes, programmable consumerelectronics, network PCs, minicomputers, mainframe computers,distributed computing environments that include any of the above systemsor devices, and the like.

The disclosed technology may be described in the general context ofcomputer-executable instructions, such as program modules, beingexecuted by a computer. Generally, software and program modules asdescribed herein include routines, programs, objects, components, datastructures, and other types of structures that perform particular tasksor implement particular abstract data types. Hardware or combinations ofhardware and software may be substituted for software modules asdescribed herein.

The disclosed technology may also be practiced in distributed computingenvironments where tasks are performed by remote processing devices thatare linked through a communications network. In a distributed computingenvironment, program modules may be located in both local and remotecomputer storage media including memory storage devices.

For purposes of this document, each process associated with thedisclosed technology may be performed continuously and by one or morecomputing devices. Each step in a process may be performed by the sameor different computing devices as those used in other steps, and eachstep need not necessarily be performed by a single computing device.

For purposes of this document, reference in the specification to “anembodiment,” “one embodiment,” “some embodiments,” or “anotherembodiment” are used to described different embodiments and do notnecessarily refer to the same embodiment.

For purposes of this document, a connection can be a direct connectionor an indirect connection (e.g., via another part).

For purposes of this document, the term “set” of objects, refers to a“set” of one or more of the objects.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

What is claimed is:
 1. A method for generating and displaying one ormore virtual objects, comprising: identifying an AR tag associated witha reading object using a mobile device; acquiring a virtual objectassociated with the AR tag, the virtual object comprises a first portionof the virtual object and a second portion of the virtual object;assigning the second portion of the virtual object to a two-dimensionalspace associated with the reading object; displaying at the mobiledevice a first set of images corresponding with the second portion ofthe virtual object such that the second portion of the virtual object isperceived to exist within the two-dimensional space as a two-dimensionalobject; detecting a space transition event for the second portion of thevirtual object from the two-dimensional space to a three-dimensionalworld space, the detecting a space transition event includes detectingan interaction between the second portion of the virtual object existingas a two-dimensional object within the two-dimensional space and adifferent virtual object existing within the three-dimensional worldspace; assigning the second portion of the virtual object to thethree-dimensional world space in response to detecting the interactionbetween the second portion of the virtual object within thetwo-dimensional space and the different virtual object existing withinthe three-dimensional world space; determining a location for the secondportion of the virtual object within the three-dimensional world space;and displaying at the mobile device a second set of images correspondingwith the second portion of the virtual object such that the secondportion of the virtual object is perceived to exist within thethree-dimensional world space as a three-dimensional object at thelocation.
 2. The method of claim 1, wherein: the determining a locationfor the second portion of the virtual object includes acquiring a windspeed and a wind direction associated with a physical location of themobile device and determining the location for the second portion of thevirtual object within the three-dimensional world space based on thewind speed and wind direction.
 3. The method of claim 1, wherein: thedetecting an interaction includes generating a dual representation forthe virtual object, the dual representation comprises a first locationfor the virtual object relative to the two-dimensional space and asecond location for the virtual object relative to the three-dimensionalworld space.
 4. The method of claim 1, wherein: the detecting a spacetransition event includes detecting that the second portion of thevirtual object has reached a boundary of the two-dimensional space dueto the interaction between the second portion of the virtual object andthe different virtual object.
 5. The method of claim 1, wherein: theacquiring a virtual object includes acquiring the virtual object from avirtual object server; and the detecting a space transition event isperformed by the mobile device, the mobile device comprises asee-through HMD.
 6. The method of claim 1, wherein: the virtual objectcomprises a holographic visual aid associated with the reading object.7. The method of claim 1, wherein: the reading object comprises anaugmentable book and the two-dimensional space associated with thereading object comprises a bounded area attached to a page of theaugmentable book.
 8. One or more storage devices containing processorreadable code for programming one or more processors to perform a methodfor generating and displaying one or more virtual objects comprising thesteps of: identifying an AR tag associated with a reading object using amobile device; acquiring a virtual object associated with the AR tag,the virtual object comprises a first portion of the virtual object and asecond portion of the virtual object; assigning the first portion of thevirtual object to a two-dimensional space associated with the readingobject; assigning the second portion of the virtual object to thetwo-dimensional space associated with the reading object; displaying atthe mobile device a first set of images corresponding with the virtualobject such that the second portion of the virtual object is perceivedto exist within the two-dimensional space as a two-dimensional object;detecting a space transition event for the second portion of the virtualobject from the two-dimensional space to a three-dimensional worldspace; assigning the second portion of the virtual object to thethree-dimensional world space in response to detecting the spacetransition event; and displaying at the mobile device one or more imagescorresponding with the virtual object such that the first portion of thevirtual object is perceived to be locked to the two-dimensional spaceassociated with the reading object and the second portion of the virtualobject is perceived to be locked to the three-dimensional world space,the second portion of the virtual object is perceived to exist withinthe three-dimensional world space as a three-dimensional object.
 9. Theone or more storage devices of claim 8, further comprising: determininga location for the second portion of the virtual object within thethree-dimensional world space, the determining a location for the secondportion of the virtual object includes acquiring a wind speed and a winddirection associated with a physical location of the mobile device anddetermining the location for the second portion of the virtual objectwithin the three-dimensional world space based on the wind speed andwind direction, the displaying at the mobile device one or more imagesincludes displaying at the mobile device the one or more images suchthat the second portion of the virtual object is perceived to existwithin the three-dimensional world space at the location.
 10. The one ormore storage devices of claim 8, wherein: the detecting a spacetransition event includes detecting that the second portion of thevirtual object has reached a boundary of the two-dimensional space. 11.The one or more storage devices of claim 8, wherein: the detecting aspace transition event includes detecting that a space triggering eventassociated with the second portion of the virtual object has occurred.12. The one or more storage devices of claim 11, wherein: the detectingthat a space triggering event associated with the second portion of thevirtual object has occurred includes detecting that an end user of themobile device has gazed at the second portion of the virtual object forat least a particular period of time.
 13. The one or more storagedevices of claim 11, wherein: the detecting that a space triggeringevent associated with the second portion of the virtual object hasoccurred includes detecting that an end user of the mobile device hasperformed a particular gesture.
 14. The one or more storage devices ofclaim 8, wherein: the reading object comprises an augmentable book andthe two-dimensional space associated with the reading object comprises abounded area attached to a page of the augmentable book.
 15. Anelectronic device for generating and displaying one or more virtualobjects, comprising: a memory configured to store a virtual objectassociated with a reading object, the virtual object comprises a firstportion of the virtual object and a second portion of the virtualobject; one or more processors configured to assign the second portionof the virtual object to a two-dimensional space associated with thereading object, the one or more processors configured to generate afirst set of images corresponding with the second portion of the virtualobject such that the second portion of the virtual object is perceivedto exist within the two-dimensional space as a two-dimensional object,the one or more processors configured to detect a space transition eventfor the second portion of the virtual object from the two-dimensionalspace to a three-dimensional world space, the space transition eventcomprises an interaction between the second portion of the virtualobject existing within the two-dimensional space and a different virtualobject existing within the three-dimensional world space, the one ormore processors configured to assign the second portion of the virtualobject to the three-dimensional world space in response to detecting thespace transition event, the one or more processors configured todetermine a location for the second portion of the virtual object withinthe three-dimensional world space, the one or more processors configuredto generate one or more images of the second portion of the virtualobject corresponding with the location; and a see-through displayconfigured to display the one or more images of the second portion ofthe virtual object such that the second portion of the virtual object isperceived to exist within the three-dimensional world space as athree-dimensional object at the location.
 16. The electronic device ofclaim 15, wherein: the one or more processors configured to acquire awind speed and a wind direction associated with a physical location ofthe mobile device and determine the location for the second portion ofthe virtual object within the three-dimensional world space based on thewind speed and wind direction.
 17. The electronic device of claim 15,wherein: the reading object comprises an augmentable book and thetwo-dimensional space associated with the reading object comprises abounded area attached to a page of the augmentable book.